CJ MF 2200 - how hot is too hot?

I am testing a Conrad Johnson MF 2200 with PF-2 pre.
I love the amp but it gets very hot. The hat sinks can be barely touched after 1-1.5 hours of playing. The sound is incredible but I think this is excessive.
Any experience or opinion on this?

I contacted CJ and they suggested that is end in the unit for check up, but stated that it runs hot.